Editor’s Note – This essay was subsequently published as:
Dillon, R.T., Jr. (2019c) Not finding Fontigens cryptica. Pp 245 - 250 in The Freshwater Gastropods of North America Volume 3, Essays on the
Prosobranchs. FWGNA Press, Charleston.
In July we met Mrs. Lori Schroeder, the remarkable amateur
malacologist dedicated to surveying the gastropod fauna of the Bernheim
Arboretum and Research Forest south of Louisville, Kentucky. And In August we convinced ourselves that the
tiny hydrobiid shells Lori discovered in debris washed along the banks of
Harrison Creek were best identified as those of Fontigens cryptica, The Most
Cryptic Freshwater Gastropod in The World [1].
But as of the spring of 2017, neither Lori, nor her
colleagues, nor indeed a team of professional karst, cave, and groundwater
biologists had found a single living Fontigens anywhere on the Bernheim
property. It was the expert opinion of
Dr. Jerry Lewis that populations of Fontigens cryptica are obligately
restricted to interstitial spaces in waters flowing through subterranean beds
of sand and gravel, equally unlikely to be recovered from creek waters at the
surface and from cave waters below.
 |
| Removing the mesh trap from a drainage pipe. |
One of the many charming gags in the 1987 Hollywood movie,
“The Princess Bride” is a scene where our hero and the bad guy wage a battle of
wits involving a poison called iocane [2].
Iocane is odorless, colorless, and tasteless. So the contest begins when our hero brandishes
a vial of poison in front of the bad guy, challenges him to put the vial to his
nose, and says, “What you’re not smelling is iocane.”
By some similar logic, I myself felt called to not see what
everybody else was not seeing in the caves, springs and streams of central
Kentucky. And I also wanted to survey
the complete freshwater gastropod fauna of Bernheim, not just its rarest
element. And I also very much wanted to
meet my remarkable colleague, Lori Schroeder.
 |
| Note the meticulous labels |
And on Saturday, 17June17, I was not disappointed at any of
the three elements of my quest. Lori and
her husband Jeff met me in the Bernheim parking lot with smiles and greetings
and a fresh pink & green gift bag.
And in the bag were four matching Tupperware containers. And in one of those containers [3] were four
zip lock bags. And in each of those bags
was a vial, and in each vial a meticulously-documented and beautifully formatted
label and a clear pill capsule, and in each pill capsule a sample of tiny snails.
We started at Lake Nevin, right by the entrance gate. No, of course we weren’t expecting to
discover any Fontigens in a small lake impounded for landscaping purposes. Poking around in the margins of Lake Nevin I
was trying to do something else it probably isn’t possible to do – overtly
correct for a known bias.
Normal sampling processes, such as the ordinary methods
ecologists use to sample biological communities, are biased against rare
species. Any element with a relative
abundance of less than one will be recorded as a zero. The FWGNA databases show the opposite trend,
however. Number theoretical analysis has
suggested that our lists of North American freshwater gastropods are biased for
rare species, not against [4].
Longtime readers of this blog are aware that I occasionally
preach little sermons [5] about a phenomenon I call “conservation-biased
oversampling.” This is the tendency, quite
unapologetic in many published surveys and vivid in the systematic collections
held by major museums, for researchers to focus their sampling efforts on
species that they think are rare or endangered.
Such efforts, driven by the availability of research funding and the
quest for more, are ultimately counter-productive.
So as of 17June17 I was carrying on the hard drive of my
computer data documenting three locations where Lori had recovered shells of
Fontigens cryptica in the Bernheim Arboretum and Research Forest. And not one single datum regarding any
population of any trash pulmonates that might be inhabiting the property whatsoever. Which I felt powerfully called to fix.
And such a fine field companion was Lori Schroeder! So enthusiastic, so interested, so eager to
learn. I got a fist-bump for a limpet. At one point about mid-morning I was poking
around in the backwater of some little stream, pulled up a dead leaf, and found
a single Ferrissia fragilis adhering to the underside. Lori was so excited that she jumped up, gave
a little whoop and offered me a fist-bump.
For a plain brown limpet, probably not 4 mm in maximum extent. A human behavior unprecedented in my long
experience.
What a beautiful day, what a lovely part of the world, and
what excellent company! Lori and Jeff
guided me to every spring, stream, lake and pond on the Bernheim property, plus
a wide assortment of bone-dry creek beds, obscure holes in the ground, and forsaken
dunes of dusty organic debris. We rode
up and down the rich old fields of the Harrison Creek valley in the back of
Jeff’s pickup truck, checking that series of mesh traps Lori and Jeff had wired
onto the drainage pipes in March.
The picnic spread that Lori and Jeff set was spectacular. In my ordinary life, the only time I ever eat
roast beef and ham together is Christmas, maybe. Lori offered 5 – 6 types of meats and cheeses
and 10 – 12 Tupperware boxes filled with an assortment of ice-cold fruits and
veggies. And I’ve got to say, that cold
bottle of Kentucky’s indigenous “Ale 8” ginger ale was among the finest things
I can ever remember wrapping my lips around.
The cool, clear waters of Harrison Creek sparkled like
jewels on that sun-dappled afternoon, a nice population of Pleurocera
semicarinata grazing lazily across the horizontally-bedded shelves of
limestone. There wasn’t much debris of
any sort in the stream, nor indeed even loose rock, cobble, or cover of any
description. At one point I stopped and
looked around myself and counted, from a single vantage point, 82
crayfish. And I paused to reflect on the
selective forces that might drive a freshwater gastropod population into subterranean
life – to quit competition for the rich periphyton resources potentially
available in such a stream and adapt to the meager rations of the lightless hyporheic
zone.
No, we did not find any Fontigens cryptica on that long,
fine day at Bernheim [6]. Last I heard,
Lori and Jeff were talking about assembling a Bou-Rouche sampling device from
the materials available at the local Tractor Supply Company, basically a piston
pump driven into the creek bed, to continue the quest.
But in my personal opinion, the world already has enough
populations of pale, white, 2 mm snails crawling through interstitial spaces
deep in our subterranean gravel deposits.
What this world needs is more Lori Schroeders.
Notes
[1] My previous posts in this series:
[3] If you’re curious, the other Tupperware containers held
a big honkin’ Campeloma from nearby Beech Fork River, a sample of Pleurocera
and Physa from nearby Sunfish Creek, and a sample of Pleurocera and Campeloma
from The Land Between The Lakes.
[4] See the analysis
of species richness in my overall Synthesis of the FWGNA Atlantic drainage data
here: [FWGNA Synthesis]
[5] I coined the term “conservation-biased oversampling” in
my post of 19Mar12, and touched on it again 6Jan14 and 16Oct15. See:
- Toward the Scientific Ranking of Conservation Status – Part III [19Mar12]
- Why Is Rarity? [6Jan14]
- To Only Know Invasives [16Oct15]
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